Electrode for arc-lamps.



G. M. LITTLE 8 8. L GUDGE. ELECTRODE FOR ARC LAMPS.

APPLICATION FILED MAY 22. 1911.

. Patented Nov. 2, 1915.

WITNESSES GEORGE M. LITTLE, F PITTSBURGH, AND BEN'TAIVIIN J. GUDGE, 0E WILKINSBURG, PENNSYLVANIA, ASSIGNORS T0 WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

ELECTRODE FOR ARC-LAMPS.

Specification of Letters Tatent.

Patented Nov. 2, T915.

' Application filed May 22, 1911. Serial No. 628,737.

To all whom it may concern:

Be it known that we, GEORGE MILO LITTLE and BENJAMIN J. GUDGE, citizens of the United States, and residents, respectively, of Pittsburgh and Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Electrodes for Arc-Lamps, of which the following is a specification.

Our invention relates to electrodes for are lamps, and it has for its object to provide an electrode having a high degree of conductivity, notwithstanding the relatively low conductivity of the refractory material largely composing it, and one that is also provided with insertion in a holder or other member, whereby a good electrical connection may be made thereto. I

In the two figures of the accompanying drawing, which illustrate two different forms of an electrode constructed in accordance with the present invention, the electrode is shown as consisting mainly of a rod 1 composed of refractory material, such as carbon, or a mixture of materials, such as magnetite, and chromium and titanium oxids, or a rod that may have any other suitable composition.

' One end of the refractory rod. of Figure 1 is provided with a transverse slot or recess for the reception of a boss 2 formed integral with a suitable metallic extension or end piece 3 that is seated upon such slotted end, the boss and slot serving to prevent relative rotation between the rod and its extension. In Fig. 2, the reverse relation of the recess and boss are shown, which, of course, is the equivalent of that shown in Fig. 1. The end piece may be composed of any suitable material, but is preferably comed of lead or a lead alloy having a relatively low meltin point so that it can be readlly cast-direct y upon the end of the refractory rod. J

,Tn view of the inaccessibility of the electrode holder in an arc lamp, it is important that the extension for the rod have substantially the same diameter as that of the "rod to permit the electrode to be conven-- iently inserted into the well known type an end piece or extension for of holder which is provided with a metallic extensible and contractible holder that grips the extension and securely holds the electrode in the lamp.

Extending through the refractory rod and into the extension thereof, or end piece, is a suitable and preferably stifi conducting wire 4, which not only affords an excellent mechanical and electrical connection between the rod and its extension, but also imparts a high degree of conductivity to the refractory rod, so that refractory materials having relatively low resistance may be employed in the composition of the electrode. It also furnishes rigidity to the joined refractory rod and extension. In order to further secure the end member upon the refractory rod, the extremity of the wire is bent laterally or is otherwise distorted or upset. The wire is secured in the refractory red by means of any suitable cement or glue. The wire at the end of the electrode remote from the end member is bent over upon the 'end of the refractory rod, in orderto prevent withdrawal of the wire from the said rod during the process of manufacture, and also to provide a blunt end for the wire which will not jam into or stick to the lower electrode. After the electrode has been burned for a while, the; end of the wire becomes fused in the molten mass or slag that forms upon the end of the electrode, so that then also there is little possibility of the wire be-' ing withdrawn from the refractory rod.

We claim as our invention:

An arc lamp electrode comprising a rod of refractory material, a metallic end extension for the rod, one of said members having an end recess and the other havin a boss projecting into the said recess, an a wire extending through the rod and into the extension and formed to prevent its withdrawal from the extension. y

In testimony whereof, we have hereunto subscribed our names this 4th day of May,

GEORGE M. LITTLE. BENJL'J. GUlDGrE. Witnesses:

- Or'ro S. SCHAIRER,

18. B. HINES. 

